Sri Aurobindo has traced the development of the vital-mind of the animal consciousness on the reactions of physical nature. The action of Instinct and Perception have been reviewed and we begin to see a systematic development of increased powers of consciousness at work as new forms of beings emerge from the Inconscience, with capacities that exceed those of earlier forms.
At this point, Sri Aurobindo takes up the influence of the evolution of a true mental intelligence as it begins to evolve and assert itself in the human being as the next phase of development.
“When human intelligence adds itself to the animal basis, this basis still remains present and active, but it is largely changed, subtilised and uplifted by conscious will and intention; the automatic life of instinct and vital intuition diminishes and cannot keep its original predominant proportion to the self-aware mental intelligence.”
Adding the mental character to this process, the pure vital intuition, expressing itself as instinct and automatic response to circumstance, is changed. “The emergence of mind in life brings an immense increase of the range and capacity of the evolving consciousness-force; but it also brings an immense increase in the range and capacity of error. For evolving mind trails constantly error as its shadow, a shadow that grows with the growing body of consciousness and knowledge.”
Sri Aurobindo, The Life Divine, Book 2, Part I, Chapter 14, The Origin and Remedy of Falsehood, Error, Wrong and Evil